JP3185673B2 - How to apply chip sealing resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of applying a chip sealing resin for sealing a chip mounted on a substrate with a resin while discharging the resin from a nozzle of a dispenser.

[0002]

2. Description of the Related Art In order to protect a chip mounted on a substrate, the chip is sealed with a resin. Hereinafter, a conventional method for applying a chip sealing resin will be described.

FIG. 4 is an explanatory view of a conventional method of applying a chip sealing resin. A chip 2 is mounted on a substrate 1 by bonding with a bond 3. The electrodes 4 of the circuit pattern on the upper surface of the substrate 1 and the electrodes on the upper surface of the chip 2 are connected by wires 5. Reference numeral 6 denotes a dispenser, which discharges a resin 8 from a nozzle 7 while horizontally moving relative to the chip 2, and seals the chip 2 and the wires 5 with the resin 8.

[0004]

However, in the above-mentioned conventional method, bubbles 9 are easily generated at the lower portion of the side wall surface of the chip 2. These bubbles 9 easily oxidize the circuit pattern of the substrate 1, and are thermally expanded by the heat generated by the internal resistance of the chip 2, causing thermal expansion and causing cracks in the resin 8.

Accordingly, an object of the present invention is to provide a method for applying a chip sealing resin which can eliminate the generation of bubbles.

[0006]

According to the present invention, there is provided a first step of forming a resin outer wall surrounding a chip by applying a resin around the chip at an interval from the chip, and forming a resin outer wall surrounding the chip. A second step of pouring the resin between the chip and the outer wall by pouring the resin therebetween, and a third step of completely sealing the chip by pouring the resin onto the upper surface of the chip.
From the steps, a method for applying the chip sealing resin was configured.

[0007]

According to the present invention, after the outer wall portion of the resin is formed around the chip in the first step, the resin is poured between the chip and the outer wall portion. To prevent air bubbles from forming at the bottom of the
Through the process, the chip can be completely sealed with the resin.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an apparatus for applying a chip sealing resin according to an embodiment of the present invention, FIG. 2 is a plan view of the substrate, and FIG.

In FIG. 1, a chip 2 is provided on an upper surface of a substrate 1.
Is mounted by bonding with a bond. The electrodes 4 on the substrate 1 and the electrodes on the upper surface of the chip 2 are connected by wires 5. 6
Is a dispenser for discharging resin stored inside from a nozzle 7. The dispenser 6 is held by a holder 9 and moves horizontally in the X and Y directions when the moving table 10 is driven.

Next, a method of applying a resin will be described with reference to FIGS. In FIG. 2, arrows indicate the movement path of the nozzle 7. As shown, the resin 8 is spirally applied from the outside to the center. Hereinafter, the coating method will be described in detail.

First, as a first step, a resin 8 is poured around the chip 2 and applied. FIG. 3A shows this first step. Reference numeral 3 denotes a bond for bonding the chip 2 to the substrate 1. As shown in the figure, the resin is applied so as to surround the chip 2 at a distance L from the chip 2, thereby forming the outer wall portion 8a of the resin. The outer wall portion 8a is desirably formed on the electrode 4 of the substrate 1, so that the electrode 4 can be securely sealed.

The outer wall 8a is applied to adjust the outer shape of the resin. As shown by a chain line in FIG. 3A, when the amount of application of the outer wall portion 8a per unit area is large, the resin flows out (see arrow a), and the outer shape is broken. Therefore, it is desirable to form the outer wall portion 8a small while pouring a relatively small amount of resin from the nozzle 7.
The dispensing amount of the resin 8 from the nozzle 7 is
The pressure applied to the liquid surface of the resin 8 inside the
It can be adjusted freely by changing the moving speed of the nozzle. Further, since the movement stroke of the nozzle 7 in the first step is considerably longer than the second step and the third step described later, it is desirable from the viewpoint of work efficiency that the movement speed of the nozzle 7 be as fast as possible to shorten the tact time.

Next, the coating in the second step is performed. FIG. 3B shows a coating state in the second step. In the second step, the resin 8b is poured out between the chip 2 and the outer wall portion 8a. Thereby, the resin 8b is poured between the chip 2 and the outer wall portion 8a. If the resin 8b is poured between the chip 2 and the outer wall portion 8a as described above, it is possible to reliably prevent bubbles from being generated between the chip 2 and the outer wall portion 8a, and to reliably seal the wire 5. In this case, the amount of resin 8b to be discharged from the nozzle 7 per unit area is set to be larger than that in the first step, whereby the resin 8b is sufficiently poured between the chip 2 and the outer wall portion 8a to generate bubbles. To prevent. Further, the outflow of the resin 8b to the outside is prevented by the outer wall portion 8a applied previously serving as a wall, and the outer shape is not broken.

Next, a third step of coating is performed. FIG. 3C shows the application state in the third step. In the third step, the resin 8c is poured out onto the upper surface of the chip 2, and the chip 2 is completely sealed. Thus, the application of the resin 8 is completed, the substrate 1 is then sent to a cure furnace, and the resin 8 is heated and hardened. FIG. 3D shows a state after curing, in which the resins 8a, 8b, and 8c are completely integrated to form a gentle mountain shape as a whole, and the chip 2, the electrode 4, and the wire 5 are completely sealed. are doing.

In the above embodiment, a chip connected to a substrate by wires has been described as an example. However, the present invention can be applied to other types of chips such as flip chips.

[0016]

According to the present invention, after the outer wall portion of the resin is formed around the chip in the first step, the resin is poured between the chip and the outer wall portion. Air bubbles are reliably prevented from being generated, and the chip can be completely sealed with resin in the subsequent third step. Further, by forming the outer wall portion in the first step, the outer shape of the resin can be adjusted, and the resin can be sealed with a good shape.

[Brief description of the drawings]

FIG. 1 is a perspective view of an apparatus for applying a chip sealing resin according to an embodiment of the present invention.

FIG. 2 is a plan view of a substrate according to an embodiment of the present invention.

FIG. 3 is a view showing a coating process of a chip sealing resin according to an embodiment of the present invention;

FIG. 4 is an explanatory view of a conventional method of applying a chip sealing resin.

[Explanation of symbols]

 Reference Signs List 1 substrate 2 chip 4 substrate 5 wire 6 dispenser 7 nozzle 8 resin 8a outer wall L interval

Continuation of the front page (56) References JP-A-3-196646 (JP, A) JP-A-8-196646 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21 / 56,23 / 28

Claims (1)

(57) [Claims] 1. A method of applying a resin for chip sealing in which a chip mounted on a substrate is sealed with a resin while pouring the resin from a nozzle of a dispenser. A first step of forming a resin outer wall surrounding the chip by coating, and a second step of pouring the resin between the chip and the outer wall by pouring the resin between the chip and the outer wall; A third step of completely sealing the chip by pouring the resin onto the upper surface of the chip.